MPL12: MD of Cardio and Lymph Systems

• Causative agents of microbial diseases of the cardiovascular and lymphatic system

  • Staphylococcus sp.
  • Streptococcus sp
  • Borrelia burgdorferi
• Modes of transmission

  • Infected blood
  • Bodily fluids (semen, saliva, mucus droplets)
  • Vectors (ticks, mites, mosquitoes)
• Prevention methods

  • Vaccination
  • Good hygiene
  • Vector control
• Bacterial sepsis

  Sepsis arises from a host's overwhelming and life-threatening immune response to infection leading to systemic inflammation. Overwhelming inflammation -> organ damage and failure. Bacteremia- presence of bacteria in the blood. Leads to septic shock, characterized by profound circulatory, cellular, and metabolic abnormalities. Sepsis leads to septic shock - the body begins to shut down.
• Bacterial sepsis

  • Fever 38.5-40C
  • Increased heart rate (tachycardia)
  • Rapid breathing (hyperventilation)
  • Confusion
  • Possible rash
  • Hypotension -> Septic shock
• Diagnostic tests for bacterial sepsis

  • CBC
  • Hemoglobin
  • Hematocrit
  • Electrolytes
  • Blood culturing
  • Lactate levels
  • C-Reactive Protein (>10 mg/dL)
  • Procalcitonin
• Antibiotics for bacterial sepsis

  • Piperacillin- tazobactam (first base)
  • Meropenem
  • Ceftriaxone (early sepsis, pediatric patient, IV Ceftriaxone)
  • Cefepime
  • Avoid vancomycin, Imipenem+Cilastatin (last resort)
• Infective endocarditis


  When bacteria enter the bloodstream and infect the heart valves or endocardium. Persistence of vegetation (clusters of bacteria and cell debris).
• Infective endocarditis

  • High grade fever (38.5-40C)
  • Murmur on auscultation
  • Fatigue
  • Petechial rashes- tiny red dots on the skin
  • Stroke in severe cases
• Diagnostic tests for infective endocarditis

  • Blood culture
  • 2D-Echo - hyper dense lesions, color white
  • ECG
  • Chest X-ray
  • CRP (C-Reactive Protein), Porcalcitonin
• Antibiotics for infective endocarditis

  • Vancomycin + Gentamicin either Cefepime/Carbapenem (Imipenem and Meropenem)
  • Valve Replacement Surgery (porcine valve or pigs valve)
• Rheumatic fever

  Inflammatory disease that can develop after an infection with group A Streptococcus bacteria (Streptococcus pyogenes). Primarily affects children. Inflammation in the heart, joints, skin, and brain.
• Symptoms of rheumatic fever

  • Fever (low grade to high grade - 37.5 - 39)
  • Painful and swollen joints
  • Skin rash
  • Carditis (inflammation of the heart)
  • Rheumatic heart disease, characterized by permanent valve damage
• Major manifestations of rheumatic fever (Jones Criteria)

  • Carditis
  • Polyarthritis - inflammation of many joints
  • Chorea - involuntary, irregular or unpredictable muscle movements
  • Erythema marginatum - lesions on the skin (White in the middle and red in the outlines)
  • Subcutaneous nodules - inflammation of lymph nodes
• Minor manifestations of rheumatic fever (Jones Criteria)

  • Fever
  • Arthralgia— joint stiffness
  • Previous rheumatic fever
  • Raised ESR (released when there is an inflammation in the heart) or CRP
  • Leukocytosis - increased WBC
  • First-degree AV block
• Diagnostic tests for rheumatic fever

  • ECG - slow ST progression, bradycardic
  • Throat culture
  • ASO titer
• Treatments for rheumatic fever

  • Benzathine Penicillin G
  • Penicillin VK - made specifically for RHD
  • Erythromycin (IV)
  • Sulfadiazine (last resort but not as effective)
  • Aspirin
  • Corticosteroids
• Tularemia (Rabbit Fever)

  Francisella tularensis can infect humans through insect bites, handling infected animals, ingestion of contaminated water, or inhalation of contaminated aerosols.
• Symptoms of tularemia

  • Fever
  • Ulcer - greenish-yellow
  • Painful lymph glands - subglandular lymphadenopathy
  • Eye inflammation
  • Respiratory issues
• Diagnostic tests for tularemia

  • Culture
  • Serology
  • PCR
• Antibiotics for tularemia

  • Streptomycin
  • Doxycycline
  • Gentamicin
• Brucellosis (Undulant: taas baba Fever)


  Brucella sp. bacteria transmitted from animals to humans through direct contact with infected animals, consumption of contaminated animal products, or inhalation of aerosols.
• Symptoms of brucellosis

  • Fever
  • Sweats
  • Anorexia
  • Malaise
  • Joint pain
  • Muscle pain
  • Reproductive organ failure -mostly in females
  • Endocarditis
• Diagnostic tests for brucellosis

  • Serology
  • Cultures
  • PCR
• Antibiotics for brucellosis

  • Doxycycline + Rifampin (2-3-4 weeks)
• Anthrax


  The bacteria Bacillus anthracis produces toxins that lead to severe inflammation and tissue damage. It enters through skin cuts, inhalation, or digestion.
• Routes of anthrax transmission

  • Cutaneous
  • Inhalational
  • Gastrointestinal
• Symptoms of anthrax

  • Septicemia and shock
• Diagnostic tools for anthrax

  • Identification of B. anthracis via microscopy, culture, and PCR
  • Serologic
• Treatments for anthrax

  • Ciprofloxacin
  • Doxycycline
  • Antitoxins
  • Vaccination
• Gangrene

  Occurs when blood flow to a tissue is obstructed due to bacterial infection, leading to tissue necrosis. The bacteria kill cells and reduce blood flow.
• Symptoms of gangrene


  • Severe pain
  • Loss of sensation
  • Skin discoloration (red to black)
  • Foul smelling discharge
• Diagnostic tools for gangrene

  • X-Ray
  • MRI
  • Blood tests
• Treatments for gangrene


  • Tissue debridement
  • Antibiotics
  • Measures to return blood flow
  • Hyperbaric oxygen therapy
• Systemic infections from animal bites and scratches

  Occur when pathogens from an animal's saliva or skin flora penetrate the skin, leading to localized or disseminated infection.
• Symptoms of systemic infections from animal bites and scratches

  • Swelling the infected area
  • Fever
  • Fatigue
  • Lymphadenopathy
  • Severe case: Systemic infection with multiple organ involvement
• Diagnostic tools for systemic infections from animal bites and scratches

  • Culture of wound specimens
  • Blood tests
  • Imaging
  • History of animal contact
• Treatments for systemic infections from animal bites and scratches

  • Wound care
  • Prophylactic or therapeutic antibiotics
  • Rabies prophylaxis if warranted
• Vector transmitted diseases


  Transmitted through mosquitoes, ticks, flies that carry pathogens often resulting in widespread epidemics.
• Symptoms of vector transmitted diseases

  • Fever
  • Rash
  • Joint pain
  • Neurological symptoms (severe cases)